My guess would be that there's a problem with the resin, likely the different components have settled into layers in the gallon container. Try getting the gallon container pretty warm and swirling it around and see if you notice any swirls of cloudy material or swirls of any kind in it. The whole thing should look consistently clear with no swirls of any kind like if it was filled with water.Mix it up really good and try it again. I've had really old flex coat settle out before and I put it in the microwave and get it pretty hot,shook the bottled until it's clear and it worked fine. Sounds like you're doing everything right and if you've had good results with FC and D2 it's got to be something wrong with the product. Likely it's been sitting on a shelf for a long time and hopefully just needs to be mixed. That's a lot of finish and a bunch of money, Hope you get it figured out.